In vitro and in vivo evaluation of mPEG-PLA modified liposomes loaded glycyrrhetinic acid.

In order to prolong the in vivo residence of glycyrrhetinic acid, a liposomes with surface modified by methoxy poly(ethyleneglycol) (mPEG)-PLA was prepared for the first time. The liposomes (C-LP) and long-circulating liposomes (LC-LP) were prepared by film-dispersion method using soybean phospholipid/cholesterol mixture (1:0.5 mol/mol), containing 5% (w/w) sodium deoxycholate, and 2% (w/w) mPEG-PLA (only for LC-LP). The diameter of LC-LP was 243.3+/-17.1 nm. The pharmacokinetics behaviors of the conventional injection and liposomes (C-LP and LC-LP) were compared after a single intravenous injection to rats. Pharmacokinetic parameters were calculated based on a two-compartment open model analysis. LC-CP had a 1.7-fold longer residence time (MRT), a 2.75-fold larger AUC and a 0.4-fold lower clearance compared with conventional injection, respectively. These results combined suggested that the LC-CP had a well-improved residence in rats.